Plotting terrain once for several parameter plots

From: Jack Glendening <ncarg_drjack_at_nyahnyahspammersnyahnyah>
Date: Thu, 27 Jul 2006 22:44:49 -0700

To pass along to other readers of this list some off-line discussion of
my previous posting quoted below, it was determined that the suggested
"animation" example, gsun09n, does not in fact provide improved
efficiency, for it simply re-computes the background each time.
However (per Dave Brown) its efficiency can be improved by setting
resource "vpUseSegments" to True - then each draw element (map,
contour, labelbar, etc) will save into a "segment file" and the Draw
routine for each element will figure out whether or not something has
changed that would cause the segment to be out of date, and if not will
re-use the stored file, thereby avoiding re-computation. However, this
will not work if gsn routines are called for each plot, as they create
new plot objects each time they are called.

Unfortunately for my real case this simple solution will not work, so I
am looking into alternative methods of improving efficiency when
plotting multiple parameters each over the same background.

>> Original message:
>>Is there an example showing how one can, to improve efficiency, create
>>a "background" plot (say of terrain and lat/long lines) and then
>>repeatedly overplot that with different parameters without having to
>>re-create that background each time? So far I have not found one (and
>>my attempts to modify an existing program to do so have been
>>unsuccessful). I am thinking of a projected coordinates case, where
>>the terrain and parameter data always have the same projection. I'm
>>trying to do in NCL what I already do in NCARG LLU program using
>>GFLAS.
>_______________________________________________
> The Getting Started Using NCL manual
> http://www.ncl.ucar.edu/Document/Manuals/Getting_Started/
> See Example 9
>http://www.ncl.ucar.edu/Document/Manuals/Getting_Started/Examples/gsun09n.shtml

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Received on Thu Jul 27 2006 - 23:44:49 MDT

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